In this question each item consists of six sentences of a passage. The first and sixth sentences are given in the beginning as S1 and S6. The middle four sentences in each have been jumbled up and labelled P, Q, R and S. You are required to find the proper sequence of the four sentences and mark your response accordingly on the Answer Sheet. S1 : Civilization dawned when early man learnt how to produce heat and energy by burning wood. S6 : When they have been used, they cannot be replaced. P : Then steam was used to produce electricity. Q : In this century great use has been made of oil and natural gas and the use of atomic reactors also has provided another source of energy. R : Much later, the first industrial revolution was based on the production of steam by burning coal. S : But none of these fuels is renewable. The correct sequence should be